Astronomy 1021 Lecture 5: Astronomy – Chapter 5

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Robert Cockcroft

Document Summary

All matter emits and absorbs light, bright at different wavelengths depending on composition and temperature. Light can act like a wave or like a particle (photon) Smooth surface: mirror like reflection in a particular direction (specular) Rough surface: scattering, reflection in a variety of directions (diffuse) This is due to the oval shape of the sun at sunset. Blue light is more easily scattered, and light takes longer path through atmosphere at sunset, more blue light gets scattered, and reason why skies are blue. Object that absorbs all light is opaque. Objects that partially absorbs light is translucent. Frequency of light that an atom can emit, dependent on the states the electrons can be. Pattern of motion that can carry energy without carrying matter along with it. Frequency: number of time per second that wave vibrates up and down. Light interacts with charged particles through these electric and magnetic fields. Do not need a medium to propagate through.